Commit 7becac84 authored by Justin Terry (VM)'s avatar Justin Terry (VM) Committed by Paolo Bonzini
Browse files

target/i386: WHPX: set CPUID_EXT_HYPERVISOR bit 



Implements the CPUID trap for CPUID 1 to include the
CPUID_EXT_HYPERVISOR flag in the ECX results. This was preventing some
older linux kernels from booting when trying to access MSR's that dont
make sense when virtualized.

Signed-off-by: default avatarJustin Terry (VM) <juterry@microsoft.com>
Message-Id: <20180326170658.606-1-juterry@microsoft.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 648abbfb

target/i386/whpx-all.c

+78 −1
Original line number Diff line number Diff line
@@ -911,12 +911,62 @@ static int whpx_vcpu_run(CPUState *cpu) 
            ret = 1;

            break;



        case WHvRunVpExitReasonX64Cpuid: {

            WHV_REGISTER_VALUE reg_values[5] = {0};

            WHV_REGISTER_NAME reg_names[5];

            UINT32 reg_count = 5;

            UINT64 rip, rax, rcx, rdx, rbx;



            rip = vcpu->exit_ctx.VpContext.Rip +

                  vcpu->exit_ctx.VpContext.InstructionLength;

            switch (vcpu->exit_ctx.CpuidAccess.Rax) {

            case 1:

                rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;

                /* Advertise that we are running on a hypervisor */

                rcx =

                    vcpu->exit_ctx.CpuidAccess.DefaultResultRcx |

                    CPUID_EXT_HYPERVISOR;



                rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;

                rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;

                break;

            default:

                rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;

                rcx = vcpu->exit_ctx.CpuidAccess.DefaultResultRcx;

                rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;

                rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;

            }



            reg_names[0] = WHvX64RegisterRip;

            reg_names[1] = WHvX64RegisterRax;

            reg_names[2] = WHvX64RegisterRcx;

            reg_names[3] = WHvX64RegisterRdx;

            reg_names[4] = WHvX64RegisterRbx;



            reg_values[0].Reg64 = rip;

            reg_values[1].Reg64 = rax;

            reg_values[2].Reg64 = rcx;

            reg_values[3].Reg64 = rdx;

            reg_values[4].Reg64 = rbx;



            hr = WHvSetVirtualProcessorRegisters(whpx->partition,

                                                 cpu->cpu_index,

                                                 reg_names,

                                                 reg_count,

                                                 reg_values);



            if (FAILED(hr)) {

                error_report("WHPX: Failed to set CpuidAccess state registers,"

                             " hr=%08lx", hr);

            }

            ret = 0;

            break;

        }

        case WHvRunVpExitReasonNone:

        case WHvRunVpExitReasonUnrecoverableException:

        case WHvRunVpExitReasonInvalidVpRegisterValue:

        case WHvRunVpExitReasonUnsupportedFeature:

        case WHvRunVpExitReasonX64MsrAccess:

        case WHvRunVpExitReasonX64Cpuid:

        case WHvRunVpExitReasonException:

        default:

            error_report("WHPX: Unexpected VP exit code %d",
@@ -1272,6 +1322,33 @@ static int whpx_accel_init(MachineState *ms) 
        goto error;

    }



    memset(&prop, 0, sizeof(WHV_PARTITION_PROPERTY));

    prop.ExtendedVmExits.X64CpuidExit = 1;

    hr = WHvSetPartitionProperty(whpx->partition,

                                 WHvPartitionPropertyCodeExtendedVmExits,

                                 &prop,

                                 sizeof(WHV_PARTITION_PROPERTY));



    if (FAILED(hr)) {

        error_report("WHPX: Failed to enable partition extended X64CpuidExit"

                     " hr=%08lx", hr);

        ret = -EINVAL;

        goto error;

    }



    UINT32 cpuidExitList[] = {1};

    hr = WHvSetPartitionProperty(whpx->partition,

                                 WHvPartitionPropertyCodeCpuidExitList,

                                 cpuidExitList,

                                 RTL_NUMBER_OF(cpuidExitList) * sizeof(UINT32));



    if (FAILED(hr)) {

        error_report("WHPX: Failed to set partition CpuidExitList hr=%08lx",

                     hr);

        ret = -EINVAL;

        goto error;

    }



    hr = WHvSetupPartition(whpx->partition);

    if (FAILED(hr)) {

        error_report("WHPX: Failed to setup partition, hr=%08lx", hr);